What does this do, subscribe you to those cars or give you them forever?

The car pass gives you access to the monthly car packs they release for I think the first 6 months (1 per month with 5-6 cars in each). In game you then get one of each of these cars for free. You can then buy more of each by paying the ingame price with ingame money.

No the VIP sub is another piece of DLC giving VIP benefits (not certain on the benefits here as there was confusion at launch over what was expected from VIP and what the game launched with). I think it gives a boost to race win earnings and additional mods.

2nd Jan

Tempted but half of the cars in the packs are a load of tosh from memory.